Raspberry Pi Opens Doors


The Raspberry Pi is a cheap credit card sized computer that has opened the doors of embedded Linux to millions of people. But in this case, it’s literally opening a door. The Computer Club at Western Michigan University had to move to a different room which brought with it a new challenge. The door handle was more difficult to turn than the old one. Nothing that a NEMA 17 stepper couldn’t handle, however.

After printing a few gears and wiring up an Easy Driver board between the Raspi and stepper motor, they had the basics of a door opener in place. A 5v relay is used to keep the power off the stepper when not in use, and a limit switch is used to monitor the position of the door handle while a Hall Effect sensor tells when the door is open and shut.

Be sure to check out the project as all source, parts list and schematics are available in case you have a simliar door that needs amending.

29 thoughts on “Raspberry Pi Opens Doors

    1. I think, stepper would make the job easier as it is very convenient to control them with just few lines of codes. The only complexity that may have arise would be that of using an additional ‘H-Bridge’ to regulate the voltage and directions of motor. Just my 1 cent :-)
      I am sure there might be some other way as well. Would love to hear your idea as well.

    1. +1
      A sweet old lady said it this way, “When all of your problems are little problems, they can seem so big”
      She was a classy old french woman who was always humble. She immigrated to the US when she was a little girl. Super great lady, I was sad when she passed.

  1. In case anyone is wondering, the source articles shows that they have a card reader retrofitted to the door. So it’s not just for the sake of seeing if they could do it. Dat WD-40 though…

  2. I’ve seen door locks/openers made with TTL or CMOS logic, ATtinys or small PICs. Using Raspberry PI for that menial task proves only that Computer Club at Western Michigan University is full of incompetent morons that can’t program a washing machine, or anything else. Next time try opening doors with explosives.

      1. It was a cipher lock made in 1980’s in Poland, which was back.then under soviet control. Microprocessors were very rare at that time, and no one ever dreamed about microcontrollers,

        Alternative to lever would be some string and counterweight which would make that lock work with servo. Also it would look more interesting.

    1. People like you are what is wrong with Hackaday, Calling people morons because you would have done it differently. Hacking is about changing something to make it do something differently. If you want it done YOUR way, Hack your own door opening device. I admit I would have done it differently too but if we all did everything the same way we would still be living in the stoneage, Hacking wouldn’t exist and you would probably be a really nice guy.

  3. “I am using a 5 volt relay, (triggered using an NPN transistor, connected to a GPIO pin and the Raspberry Pi’s 5 volt output) to turn off power to the Easy Driver board when the stepper is not in use.” if only…somehow…the driver had a sleep function pin….if only.

  4. Never ceases to amaze me how people find fault in work others have done. Gears work, levers could be used. But, then again the door had a handle and a key already, so it could be argued this was not needed at all.
    This project has user authentication, access tracking, etc. Could it be done with different, with more minimal hardware? Yes. But, the real point here is that someone DID something. AND, took the time to document it (anyone who has taken the time to do documentation, knows how much an effort that is. ;) )

    Rather than moaning “Oh, my way would have been …”, why not actually DO something and offer it as alternative? Or, take a piece of it and simplify it to improve the design. (possible answer: the naysayers are too busy judging others to actually DO anything else?)

    Besides, easier, better, cheaper, etc. may not even be a consideration for a “one-of” situation…

    (And, full disclosure, I’ve been guilty of a snarky remark or two in my lifetime.) :(

    1. I’m guessing most people didn’t read the full article, which explains that the Pi now talks to a backend server for authentication/validation/registration and reporting the status of the door. It appears to be hooked into an IRC channel as well.

      Yeah, you could’ve used $microcontroller and an ESP8266 or an Ethernet adapter, but I bet using the Pi made it a much quicker project.

    2. right, raspi = a tool, your programming skills on raspi = another tool. arduino = tool etc.
      each one has some certain recipe of tool 1 + tool 22 to achieve the solution. Most people seem to miss the point: the way it is done is usually the easiest and cheapest for the hobbyist in terms of money and time.

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